An intrinsic property of a substance is a property that is inherent to the material itself at the molecular level. An intrinsic property does not depend on the amount of material that is present. An extrinsic property is one that does depend on the amount of material present or some other outside factor.
Color is an intrinsic property. If you take a red sheet of paper and tear it in half, the color of the halves has not changed from when it was a single sheet. More technically, color is determined by which wavelengths of light in the visible portion of the spectrum are absorbed and reflected by the molecules of a substance. This means that color is determined at the molecular level of the substance, hence it is intrinsic.